The infrastructure of many train operators dates back from a time when leveled boarding from the passenger platform to a railcar, and vice-versa, was a consideration of second importance, if at all. Often, passengers would need to step up or down inboard a railcar and that was just the way it was. Nowadays however, with accident prevention and easy access for passengers with disabilities being of prime importance, such leveled boarding is an absolute requirement. Consequently, modern vehicles have to be designed to provide this leveled boarding even when used with infrastructure of years gone by.
Height adjusting systems capable of varying the height of a car body have been used for a while. U.S. Pat. No. 7,520,494 to Gaile and U.S. Pat. No. 8,235,366 to Anton disclose a height adjusting systems positioned between a bogie and a body of a railcar capable of precisely pushing upwardly the body at a right level for leveled boarding. However, some railroads require the railcar to run at its highest position between stations because of limited clearance to the ground. Consequently, the height adjusting systems need to continuously operate for the railcar, which would otherwise normally run at its lowest position, to have sufficient clearance to operate on the tracks. This makes the whole train vulnerable in case of failure of the height adjusting system.
Capable of precisely addressing this drawback, published U.S. patent application no. 2016/0176417 to Gaile discloses a height adjusting system capable of pulling down the body of the railcar when in station. Because the railcar runs normally at its highest position, the train is not vulnerable to failure of the height adjusting system. Nevertheless, as disclosed, some components of the height adjusting system are highly stressed when in use, making these components prone to failure.
There is therefore a need for an improved height adjusting system.